One who eats at home, embarrassed to go about outside (5)
I believe the answer is:
diner
'one who eats at home embarrassed to go about outside' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'one who eats at home embarrassed' is the wordplay.
'one who' becomes 'dr' (from TV series Doctor Who).
'eats' is an insertion indicator.
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'embarrassed' becomes 'e' (this might be a standard abbreviation of which I'm unaware).
'in'+'e'='ine'
'dr' enclosing 'ine' is 'DINER'.
Can you help me to learn more?
(Other definitions for diner that I've seen before include "Restaurant customer" , "(One using) restaurant car" , "Buffet car" , "US eatery" , "One eating a meal" .)